Yes, that is right -"inselaffen"(island apes) is the expression, but to be fair, I only ever heard this rarely and it is so insulting, that the vast majority of Germans would not say this.
We go camping in Holland near the German border, and whilst there is now much intermingling between the 2 nations, when you actually speak to the Dutch in private, as it were, the dislike of the Germans comes out. The wounds from the war when the Dutch suffered greatly during the "hongerwinter"...